Can you build a dialog box to fill a column
 

I have an application in which the client would fill a column with numbers.
The column would be a cash flow. So it may have cash in the first year only,
for n number of years, start and stop and restart, etc.. Bell and whistles
would be to include an inflation factor so that the cash flow increase by x%
for n years.

I thought about manipulating a column directly on an "Input' sheet. I've
also considered manipulating an array and then commit that to the "Input"
sheet.

Has any one built something along these lines? I want to limit the users
access to the data by allowing input by dialog box only.